The over-the-counter drug industry, prompted by the recall of threecapsule medications tainted with rat poison, added $700,000 to a reward fund, but a man identifying himself as the tamperer said in a telephone call that the money "isn't enough. I'll take more." The call came to the CBS affiliate WCAU-TV in Philadelphia. The reward fund, established after the 1982 Tylenol poisonings that killed seven people, swelled to $900,000 with the announcement by the Proprietary Assn. The trade group acted three days after Contac, Dietac and Teldrin were recalled.