Last data in used first, leaving other to expire

5.56 GB of data -from a top-up- was left unused on 01 September 2015 and even if it was due to expire on 09 September 2015 (when it all disappeared from the record unused but fortunately I had made screen grabs) because the contractual data is allocated on the first of the month and as soon as it does, it starts depleting that allocation leaving unused available data to expire unused. It is that data that is allocated LAST that is used first according to Kaulsome who called on 13 September 11:50 after studying my screen grabs. she said \it is a business rule"that I had signed and thus had to accept. I refuse because with the sophisticated IT programmes"