I had been using Verizon dsl, as well as local phone service. I had a problem with the dsl and they sent me a new modem, noting that I should return the old one, else I would be charged an unknown fee. The new modem worked. I did not get a return label for the old modem. Twice customer service people said that they would email a label. It didn't happen. A third time I was told I could take the modem to a UPS outlet and they could charge Verizon's account. That did not work. Another call revealed that the customer service people were not able to email a label, but that one would be sent by US mail. I was not impressed with the technical expertise shown.
I decided to switch to FIOS, for internet and telephone. I wouldn't save me any money (in fact it raised my bill), but I thought that the improved service would make it worthwhile. The service was installed without an problems, though I found it interesting they were not interested in the dsl modem that has been so important previously.
I have not noticed a significant improvement in internet performance. Then a few days ago, my wife's FIOS (we have two houses) failed completely (TV, internet, telephone). I called tech support on my cell phone. I was told that to reset the system I would have to disconnect the battery. The instructions I was given over the phone were impossible to carry out. I would either need a specialized tool or an incredibly small hand, roughly the size of a marmoset's. When asked about having a tech person coming out to do it, I was told that there would be an unknown fee. Fortunately the service restored itself after a while.
After that experience I realized that I did not trust Verizon, since if they are unable to properly deal with a simple matter such a emailing a mailing label, can I expect them to properly deal with other problems that might arise. Since there was not a significant improvement in services, as well as an increase in cost, I tried to cancel. I found that I cannot and that choosing FIOS is an irrevocable decision. I voiced my concerns to someone on the "presidential escalation team" and was basically told that I am stuck with what I have. I am not a happy camper.
I'm sorry you are having difficulty. An agent with access to your account will reach out to you directly by email, private message in the Forums and/or the billing telephone number on your Verizon account for more information or to help you resolve your issue.
Verizon hasn't been very good at times with wanting used equipment back and sending return labels. You'll need to spend some time on the phone to get an agent to send one back, or you'll have to hang onto it in case they do wish to get the modem back someday. Failing that, sell it to someone who'd like it.
For speed improvements on the FiOS service? There should be a good difference between DSL and FiOS. It might be a case of your PC not being tuned up to take advantage of the connection, or it could be the connection medium (Wired, Wireless), or it could also be the websites you're connecting to. FiOS best shows when you have a small browser cache, fast DNS servers, and the PC has been tuned accordingly.