Where it is shown to the satisfaction of a rating authority that any amount has been paid to them in respect of rates by reason of an error of fact, and the amount is not recoverable apart from this section, the authority shall repay the amount to the person from whom they received it or to any other person appearing to them to be entitled to that person's interest:

Provided that no repayment under this subsection shall be made after the end of the sixth year after that in respect of which the amount was paid, unless application therefor was before that time.

In this section the expression " rating authority " has the same meaning as in Part XI of the Act of 1947.