The PTL religious television network based here claims that a computer problem has prevented it from receiving at least $13 million in donations from its jewers and supporters, and is responsible for its $4 million debt.

President Jim Bakker said the problem resulted in more than 200,000 letters going unanswered and in failure of supporters to receive envelops in which to mail in their monthly pledges. He said many supporters felt neglected and stopped sending in pledges, which in the past have totaled $1 million a week.

He said discovery of the problem will enable PTL to eliminate its indebtedness within three months.

"I believe in 90 days, we will be totally out of bedt," he said. "There is no doubt about it. This is the problem. I know for sure."

As the result of the computer mix-up, he said, PTL has not been sending out receipts for pledges, Bibles, records, educational materials, gifts and other matter. Because of a computer programming error, he said, the computer was printing duplicate mailing labels, which caused PTL to be sending duplicate material to honor a single request.

To correct the problem, he said, PTL is working 24 hours a day to answer mail. Sixty speed typists have been transferred to the computer department, where they will be given a crash computer course in order to catch up with the backlog.

The biggest part of PTL's reported indebtedness and financial problems has been its projected $100 million campground and university complex just across the state line in York County, S. C. Work there was halted in August by the general contractor because PTL was more than $500,000 behind in its payments.