I would be ticked
Had a similar situation happen to us. We had just bought a new oven. I used it maybe a dozen times, then decided to put the clean cycle on (it was getting toward summer and I didn't want to clean it then). Well, the oven quit working after the clean cycle. It wouldn't come on at all.
The repairman (I'm not going to name the company) came out to fix it. It needed a part (I think the computer control on the front shorted out). It took this company almost 3 MONTHS to get us the part! Thankfully- it was summer, and just too hot to use the oven anyhow, so I used the grill for everything.
At least I didn't have to pay for it, it was under warranty.