You do realise that initial and final bills are rarely the exact amount a normal month will be , the period being charged for can be for more that a month ( , if joining part the way through a billing cycle it may be for more than 30 days ) , they can include one off charges like delivery of equipment, or ‘connection’ charges etc , if I were told £15 a month I wouldn’t expect the first payment to be £15 but more ….,
although it may be an error , it’s much more likely that the first payment is larger than what the subsequent ‘normal’ monthly fee will be ,
