We had a Domo supplied when we eventually got our TRAC phone installed.  After struggling with the instructions in Spanish we downloaded the instructions in English from the internet by a guy who had kindly translated them.  I imagine this was the original Domo so don’t know anything about Mark 2’s etc.  We then realised we were paying monthly for the privilege of having a Telefonica phone so decided to buy a different phone altogether.  There are many cheap phones on the market, some of them having instructions in English or giving their web site address where instructions in English can be downloaded.  The Domo can be returned by telephoning the English speaking service, explaining that you want to return it and you will be given a reference number.  We live in Valencia region so took it back to the Telefonica shop in Valencia and the rental charge was then missing on our next bill.