It looks like a 5" media filter? If so it shouldn't matter as the main purpose of the arrow is to allow the filters integrated support to keep the media from collapsing into the blower opening up an air bypass. A 5" filter would not be as easily bent as a 1" filter.
Since it's dirty enough to shake off clumps of dirt already, I'd make sure the rest of the trash is out of the return ducting and then just buy a new one. Why didn't the installing company clean the trash out first?
thnx! not sure why he didn't. i will no for next time to ask this valuable question.
once again thank you all for taking the time to answer my qs. have a great day.