Thanks for your post and welcome to our community.
I'm really sorry that you're having an issue with unwanted messages on your new SIM Only deal, I can appreciate you're keen to get this sorted.
Just to confirm, if the SIM is in a router how are you viewing the messages?
As you've taken out a SIM Only with us we'll have provided you with a mobile number. This number could have been recycled and may previously have had these messages sent or some companies try their luck and enter random numbers.
We can look at changing the number for free as it's the first time and see how it goes from there.
If that's something you want to do then please pop me a personal message
I have recently joined the Virgin family and before I even be one month to the company, I have received just today a message from Wahoo saying that I will be charged 4.50 GBP a week for a service that I have never signed in. I know it is a spam. I called the customer service and they said that I have to either reply STOP or call the number that they provide to stop any charges. But by doing so, I verify my number to the spam. I asked to block premium msgs to my phone, but the customer service said they can't do it as it is a third party company. What should I do? SOS