wilting passionflower

It could be several things.

If the plant was in a sheltered spot in the garden centre and it is now in a spot exposed to full sun and wind, it could be that.  Yellowing wilting leaves can indicate it is too wet, brown too dry.

If it one of the exotic coloured ones, these come from Holland and are notoriously difficult to keep going.  They get pampered in a climate controlled glasshouse to bring them into flower and look spectacular, but out in the real world, they are divas.  When I worked in a garden centre, you would groan when the group buyers sent these in.  At least half those sold would come back for a refund