Mr. Lube Canada review: Overcharge for an oil filter cap replacement

I took my Toyota RAV4 for an oil change at Mr. Lube (address below). I told them that I have detected an oil leak coming out from the oil filter cap, they checked it and told me that the oil filter cap has to be replaced and it costs $199, I told them to replace it, I paid them for the oil change ($116) and for the oil filter cap replacement ($199.99). Then I had a feeling that the $199.99 for the oil filter cap only was too much. So, I decided to check with one of the Toyota dealerships in town, at the Toyota dealership, they told me that the oil filter cap was only $44. I called Mr. Lube to ask them why I was overcharged for the oil filter cap, they said they showed me price and I agreed! I told them that I am not a dealership or auto-parts specialist to know the actual price of an auto-part on the spot. But I trust Mr. Lube as a company and consequently their employees. Mr. Lube employees should have acted ethically and honestly instead they charge their customers random amounts of money that are disproportionate to the service done and/or inequivalent to the fair market price of the replaced part(s). Such behavior would affect the reputation of Mr. Lube negatively.