BAD Debt vs VAT Return

Hello,

I have slight problem as we have some invoices with October date last year. These invoices are not recoverable as this BAD DEBT. There is few of them so I wanted to write them off before end of the Q1 to recover VAT we’ve have paid for them in last VAT return but when write them off as BAD DEBT with any date in between 01.01.2018 to 31.03.2018 the VAT amount claimed back is not being show in VAT return report for the Q1 and instead of Q1 it shows that those invoices were put forward in the next VAT return = Q2.

Any thought please? Best Regards, Marcin