Maternity allowance as AuPair (London)

Hi! Has anyone ever received Maternity Allowance after working as an AuPair? I have a contract, but my employers don’t issue payslips. I have written that on the notes part on my claim. So I sent Bank statements as an alternatively to prove my income for my 13 weeks of test period. But I still received a message saying they require the payslips and cannot accept statements. What do I do? Has anyone ever been in this situation? Any advice?