Several problems since new 5 years ago

This was to be our last refrigerator. Now, I'm wondering about that. It was expensive . . . almost $3,000 expensive! After a couple of year, the interior lighting quit working. fixed under extended warranty. But immediately after that, Ice began to form around the freezer drawer. Called them back out. Different guy came. Said that there was a factory fix for that, a second fan. He disassembled the refrigerator and installed the kit. Within a week, we saw that the ice was still forming. Called them back. Another repairman came out. He said that the issue was the freezer drawer slides and replaced them. Within a week , ice began to form again. Called them back. They blamed us for not keeping the freezer drawer shut! None of this was happening before the 1st repairman came out to replace the interior lighting. Then, it was constant. Then, they blame us. Then, the extended warranty ran out. I'm on my own. So we just keep a heat gun handy to thaw the frost and ice from the freezer drawer now every 2 -4 weeks; less often in the dry winter when Relative humidity is lower. NOW, new problem. The freezer isn't defrosting. Frost builds up on the top of it until the evap coil circulating fan blades start hitting it making a buzzing sound. I removed all the drawers and defrosted the area. Then quite. But of course, it frosted up again because I only alleviated the symptoms and didn't fix anything. Called another repair company out. He diagnosed that the entire defrost section needed to be changed. $620.00. I've decided to order the parts that he was going to order and do it myself. I mean, I can't do any worse than the previous servicemen.