Hi-Tec Ula Ultra sandle design fault

I bought a pair of Ula Ultra Hi-Tec sandals in size 12, only to find that the upper strap is so short that I can barely reach the Velcro-to-Velcro connection, overlapping less that 1cm on an 8cm Velcro strip. When I put my required inserts into the sandals, I can't fasten them at all. From my perspective, they have made a design error and not taken into account the girth of a size 12 foot. I contacted Hi-Tech but they basically say I tried on the shoes and bought them, so my bad. I contracted a cobbler to correct their design fault, so Hi-Tec can go...…...