1995 Other Mitsubishi Models transmission

Ok my sons car broke down with trans out in October, the company that has the car has had it for 3 months we have gotten car back twice and transmission goes out again within days they put an exterenal cooler on it and have rebuilt transmission 5 times they are now saying there has to be a wiring issue and want more money. But there were no problems until my son was on his way home from school he said the tactomoter quick then he had blue smoke coming from back, he pulled over and we had it towed 200 miles home. Please help with any info I could use. (By the way everytime the trans goes out they are saying that everything inside is melted planets gear and all)