What to do when a senior has signed a contract that is grossly over priced for equipment they cannot afford on fixed incomes?

Many states have a 3 to 7 day period to "roll back" or invalidate these type of contracts. Check with an elder law attorney, your local sheriff's office or the local aging agency immediately! In fact, start with the sheriff's office so they can start looking for this guy if he's still working the area door to door.

Check thru all of the paperwork. There may a form called Right of Recision. It will spell out the time period that the consumer has to call and cancel the contract without penalty. If there isn’t one, call the Consumer Protection Bureau And report. If there isn’t a Consumer Peotection Bureau in their State, call the State Attorney General’s Office.

This is obviously financial exploitation of a vulnerable senior.

Report this to the authorities and call the company that sold them an 8500.00 vent cleaning. That is so blatant it's not even funny.

As for the AC I would not let them remove it, the company is obviously not worried about their integrity so it is reasonable to assume they will take their AC and leave them in the lurches with no unit. I imagine for 8500.00 it is a dual unit for cooling and heat.

Get these crooks nailed!

I assume the work is already done? If not, cancel it. If so, call the company and give them the chance to do the honorable thing. If they choose not to, call your County's Office of Services for the Aging and your District Attorney's office. If your local television station has a consumer reporter, call him/her also.
There are SO many service and home improvement companies that prey on the elderly.

I took my Mom's checkbook, credit cards and any cash out of the house. Any people we deal with landscaper etc know they can only talk to me or they don't get paid.

It may be late now but usually there is a 3 day "cool off" time when the contract can be cancelled.
If the person that signed the contract is not capable of entering into a contract then it could be cancelled.
Has the person that signed the contract been diagnosed with Dementia of any kind? If so contact the company and inform them that due to a medical condition the person that signed the contract is not legally able to enter into such a contract.

If it’s paid but the work has not started, call them immediately and cancel the work and ask for a refund. Do you have POA?
Anyone with dementia cannot make their own decisions.
We had to move dad closer to family. He had new inground sprinklers installed (he already had them), he had his concrete sidewalks redone (because the neighbor had them done) paid both in CASH... and was already calling the concrete sidewalk guy back to come do his “blacktop” driveway when we intervened. We told the guy not to come- that dad has a brain injury and is not able to make decisions. In two weeks he spent over 10,000!
can you takeover finances to prevent further incidents? Get POA if you don’t akready have it.. put a limit on monthly credit card transaction amounts, take the checkbook... limit ATM withdrawals...do whatever it takes to prevent future scams!
How about a “no soliciting” sign?
Unfortunately, there are people out there who truly take advantage.

Whomever you report this to make sure you tell them he got them to inflate their income. Who wrote the number down? Stop payment at bank ASAP.

Has he paid them in full already? Read the contract, see if you can cancel. If not, it is a scam, so cancel either way. The only problem would be getting his money back.

That's a lot of money. I'd consult with an attorney without delay to get all the possible remedies and defenses. Some contracts are just Unconscionable. It may be unenforceable.