Should I accept this print from a print company

I have been trying a few different companies for my printing needs (i can do up to A4 myself ok but no bigger and need quite a few A3)

I have just had some done through file-print who have used "print concern" to do the printing.

I have recieved the order and all 10 prints have the same issue which i believe to be horizontal banding. (se 3 pictures below).

I havehad this myself when printing and done printhead cleans and printhead calibrations and sorts the issue but print concern are saying that they cannot produce a print any better and will not do a reprint.

To me it is not acceptable as it is clearly visable and distracting.

I have been offered a full refund if I send them back or 25% refund if i keep them but It now means a delay getting them to my customer and reprinting with someone else as No way will I supply him these prints as it will only give me a bad name due to the quality.

Has anyone else had issues from printing companies and do you think they should be reprinting tehm for me?