Need help with create listing

I need help creating an offer, the send e-mail and call me options do not work - silence on the phone or someone pretends not to hear or hangs up after a second. I have several open issues and I can't get answers to any of them. I'll start with the first one, namely. Someone in 2019 created an offer, i.e. blocked the EAN, entered the manufacturer and brand that he invented himself and is not real, in fact, he offers things with the product that I do not intend to offer. This product has not been offered for a long time by this person and I cannot change the back, the description (the products have changed since 2019) or the photos. I cannot create a new offer because the EAN is used and some errors keep appearing. What can I do with this? Amazon is not a friendly place when you have problems.