King mattress only 75, 76" long

Hi all,
I’ve received two King mattresses now from a family-owned firm that are only 75 or 76 inches long. The company is trying to convince me that this is in the range of normal since the mattress mostly covers the boxspring. The bed is several inches short for my king sized bedframe. Should I have to accept a king mattress that is nearly square and at most 76 inches long (according to their measurements-- I’m not getting that long)? Thanks.

Hi elenim.

The standard king mattress is 76" x 80" where a CA king is 72″ x 84″ - is it possible your frame is for a california king?

NikkiTMU

Standard king frame. The mattress is just very short of 80". The company is suggesting that it will expand over the next few days…
Thank you!