A Team Appliance Repair

Recently, when I started my Miele dishwasher (that until then was working fine), I heard the water running and there was dripping under the sink from the black U-shaped pipe (p-trap). Miele referred me to this repair company. They told me they charge $80 for a visit, but when they came they said that they will fix the problem of leaking for $328. I agreed to pay that amount to fix the leak. They forced me to send them an e-transfer for $328 immediately; they do not accept credit card payments. However, after my e-transfer, they said they could not fix the problem because they needed to replace a few parts, like cooling, fan motor, blower sensor , etc. for an additional $1,431 (for the total of $1,759). I refused ordering the parts, being suspicious of the large unexpected amount. I requested that they refund me the $328 that I paid, as they did not repair anything. They refused and tried to convince me to order the parts. After they left, I found that the leaking came from the drain line because the squeeze clamp was loose. Once it was tightened, there was no leak and my dishwasher works fine. Unfortunately, I paid them $328 for doing nothing, and they were going to extort $1,759 from me.