I don't know if you can buy them separately, but it is worth going into your local GoOutdoors (if there is one local to you) and asking in there.
My teenage son has an OEX tent and after a garden sleep over with a mate, he discovered one of the poles had snapped badly. The specific poles are not for sale separately but we went into the local shop to get their advice and they actually GAVE my son a replacement pole for free. Then then next time he got his tent out to camp (in Wiltshire so almost 300 miles from home) he discovered another pole had actually broken as well. We went into the Swindon GoOutdoors and whilst they didn't have the right pole, the guy in there not only provided an OEX replacement, he cut it down to the right length too - and again gave it to my son for free.
Some people are a bit sniffy about GoOutdoors, but they were excellent in helping out with broken poles. They may just be able to source you extra pods.
Not such a silly question its been known. We put it up to cheat it Sunday there was a pole missing & the bedrooms. I'd got a spare pole so we just need the bedrooms.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.