I keep receiving calls from a telephone number  0176 88854748, which I believe is affiliated with o2. I don’t want to be contacted by phone, especially while I’m at work, and would prefer contact by email. I can’t delete my telephone number from my contact details - how can I ask O2 to contact me by email, not by phone?

EDT: verschoben von “Mein O₂, O₂ Online & E-Mail” in Englisch: Mobile     o2_Maria, 10.08.23,  19:37 Uhr