I took my car for a major Service (***km) on the service book the said they change oil and changed spark plugs but after noticing my car didn’t have power even after the service i got a mechanic to check my car and discovered that the plugs were very

I took my car for a major Service (***km) on the service book the said they change oil and changed spark plugs but after noticing my car didn’t have power even after the service i got a mechanic to check my car and discovered that the plugs were very old and worn. The 2 jobs they claim they did which they clearly did not is not the only things listed under their major service. I have been warned before that they are *****ulent but never listened just wonder how many times they ripped me off since i started taking my car to them for service