PCS Paypal Top-Up Tickets

Hello everyone, I have a question: I posted an ad on Camara occasion to sell an old digital camera, so far so good. I was contacted by a certain Mrs. Sylvie Chapoteau. She asked me if I had a PayPal account, to which I replied yes, I had just created it. So she said she would pay me through that (50 euros total), alright. I went to the post office and sent the package with the correct address, etc. The package came back to me... The lady hadn't mentioned that she lived in Switzerland, so at the machine for postage, I didn't realize it was not just for France, etc. Well, that was my mistake. I contacted the lady, who told me she had given the wrong address. Already a bit suspicious, but I ignored that. She sent me her new address and the package was sent again. A few days later (about 10/15 days), it arrived in my mailbox. I contacted the lady again, who said she was away for work and that her husband couldn't pick up the package in her place, so it was returned to me. In the meantime, I had to buy initially recharge tickets of 150 euros each (I don't remember how many, maybe 4 or 6). Panicking, I contacted the person who assured me that she had experienced the same on her end, etc... she explained that it would be reimbursed once all the tickets were purchased. And naively, I got caught in the trap. Then we moved to 15 tickets to pay the Swiss tax. Now I'm being asked to pay a tax for the Swiss general tax office. At this point, I have serious doubts; I looked up information online and found a story that coincides with mine. What should I do to find out if this is a huge scam? I've already put a lot into this (18 tickets at 150 euros each, do the math), should I file a police report? I'm afraid I'll never see my money again; I've gone into debt for this mess that I regret!! All for 50 euros too.... Less risk with a bounced check.... Please, if you've been through this, I ask for your help and advice, please. Thank you all.