So I took my Toyota to a different Toyota dealership service department today and on the receipt it says they put in 5W-20 oil when my car officially takes 5W-30 oil. and has just over 120K miles. So should I call them up, demand a refund and then take my car for yet another oil change at my usual dealership and get the right oil put back in?
Yes. I would ask for a refund and have the correct oil installed.
The thinner oil will not likely hurt, but no sense taking a chance with their error.
This is another reason not to take your vehicle to the stealership especially after warranty is up. It’s better to find a good, honest independent mechanic to do the job (if you don’t DIY) over the dealer.
Please listen to DayWalker and never take your car to a dealer unless it's for warranty work.
Okay, thanks for the response -- I did get another oil change the very next day from my usual service department and contacted the one that made the mistake. The service manager there acknowledged the mistake, apologized, and has submitted a reimbursement request for a refund check to be mailed to me in a few weeks.