local housing allowance for pensioners

Other

we have a pensioner who was receiving £90 per week to cover his full rent on local housing allowance. it is paid direct to the landlord. we believe when LHA was first introduced, pensioners were paid the full rent being charged. now leeds city council are saying this was a mistake and have reduced his rent payment by £3 per week. they also claimed an overpayment had occured though they say we do not have to repay this overpayment. there seems to be some info on pensioners and LHA in section 14 of housing benefit General LHA amendment regulations 2003. Is there anything in the legislation to say pensioners get full amount of rent charged rather than set LHA amount.