false payment made on my behalf

I receive a phone call saying dat im owing telkom mobile wen I know dat my acc has prescribed. ..I was out of de country for three years and prescription act of 1969 says that if des no contact wit a debtor de account must prescribe.what amazr me its dat one of de debt collector called me nd said that iv once made a payment of 50 rand in this account which I dnt knw ..my concerns is dat I wnt to knw where the 50 rand get paid nd when its like this company made a payment on my behalf tp interrupt the prescription ....