0845602111

You've signed up but maybe forgotten how TPS works, it's a voluntary system for reputable UK-based telemarketing companies to help them avoid cold-calling UK residents, it does not stop: fraudsters, spammers, phishers, overseas-based call centres & ID theft crims, generally, nor bottom-feeding pond lo-life scumbags.
Being X-D is irrelevant, they use autodiallers to call '000s of potential subscribers, EVERY minute of every hour, sadly fooling the vulnerable, unsuspecting or naive to part with personal data that will result in financial loss and hardship for some.
Meanwhile, THIS number is what happens when a SMS (text) is sent to a landline, mostly by mistake, but ANY number can be disguised (spoofed), which telecom providers can't be "bottomed" - ahem - to prevent.
Although it's a BT operated text relay service, most other providers, like Sky, Voda, Virgin, TalkTalk etc have to use  the BT network being obliged by statute to deliver calls and messages, like the Royal Mail, being once the sole service providers for communications whether physical or electronic.
Best get used to it.
Previous comments, many of them, already explain how to manage or avoid 0845 602 1111 messages so I shan't bother to waste more time on what YOU might do to help resolve a similar issue.
Hint: IT'S AVAILABLE ON ALMOST EVERY PAGE IN LAST 12+ YEARS.