customer service

I’m looking into libre for the first time. I see that there is a community “help”. And I appreciate that. But is that the only help resource, is there a libre customer service that I could contact/phone number?

LibreOffice is maintained by community, which consists of volunteers and paid developers/companies that independently work on common codebase under the umbrella of non-profit organization “The Document Foundation”. The community, as well as The Document Foundation itself, can only provide community support. If you need greater level of help, you are welcome to contact any of certified professionals that provide paid support.

Hi Kosta, nice that you are interested in LibreOffice. First of all, here at ask.LibreOffice help user other users.
LibreOffice itself has an offline help. You can get a lot of information about LibreOffice on the main website.
Here, for example, the page with the documentation:

https://documentation.libreoffice.org/en/english-documentation/

In addition to this ask page you can also sign up on the mailing lists, so you can be helped with questions:

https://www.libreoffice.org/get-help/mailing-lists/

A telephone number for customer service does not exist. Remember that most project participants are volunteers.

Hi, I have used Libreoffice for quite some time but recently when I try to open a document it tells me that the documents do not exist. I would be glad of your help please. Thank you.

The appending of questions is not desired.
Please ask your own question and do not attach it somewhere. Thank you.