Amount excl. VAT does not match total amount – error message

Dear Sir/Madam,

I paid 27 euros incl. VAT for business cards.

I have to enter the amount excluding 21% VAT myself, but I keep getting an error message because the total amount excl. VAT and the amount excl. VAT do not match.

However, this is very difficult because there are many digits after the decimal point: 27 euros incl. VAT and 22.3140495868 euros excl. VAT. The programme does not allow me to type the last two digits after the decimal point. How can I resolve this?

Many thanks