Farmboy is right DO NOT fight them in their arena, (banners).
Competition is a good thing, it will show you what you are doing wrong, force you sharpen your skills and business approach and on the other hand could do you in.
Fine another source for your banner supply and take the advice of George Patton....."you don't win a war by dying for your country (cause), you win by getting the other son of a bitch to die for his"
Sharpen your screen printing skills and take your battle ready energy and refocus it on what you already know.
Think about this....what are you doing that sent the message to your now competitor that there is money to be made printing tee shirts....think like your competition
mooseman