Is this seller trying to scam me?

I ordered a inner tube fot my electric scooter with a 45 degree valve. The seller messaged me that he doesn't have it and if he can send me the 90 degree angle and I said no and that he can cancel the order and give me my money back. I didn't do anything. Then the next day he updated the status to shipping and a tracking number that if you actually check dhl is not in their system.

Then he messages me that he cant cancel the order and I should. But if I go to cancel I can't because it's marked as shipped. If I go farther into the return items option the only option is the free pickup for returns. But I can't return since he hasn't even shipped.

I'm not sure if I'm getting scammed or not. If someone comed to collect I can only send back an empty box, and the same day he can send the wrong item and then he can claim that I scammed him by returning an empty box. I tried the support chat but theres just a bot that doesnt understand the issue.

The only thing I can is wait so he sends something even if its the wrong item then return it. Everything else I will look like the scammer.

What would you do?