I used to drink IPA and Tetleys, but not much chance of buying it here.
I really do sometimes wonder which country you are living in. There's IPA all over the place in Poland. Even Zywiec now make an IPA, although as it's made by Zywiec it'll be chemical-filled swill which is good only for giving hangovers. Have you really missed the craft beer revolution that started a few years ago?! Even Grupa Zywiec now have a pseudo-craft brewery operation!
If you tell me the names of the nearest biggish towns to you, I'll tell you were you can buy proper beer. Alternatively just order from Piwonia (piwonia.piwazdusza.pl); they will deliver a crate of 20 bottles to your door for 20zl.
If you want some higher-end international beers, check out smakpiwa.pl, they have an utterly awesome selection, I particularly recommend the Mikkeller Do Nieba (an IPA from the legendary Mikkeller brewery made specifically for the Polish market and using Polish hops), Beavertown 8 Ball IPA, Siren Half Mast session IPA and Brewdog Dead Pony Club pale ale. All of those will make Tetleys taste like Carling Black Label.