Vodafone — Unknown number [protected] call forwarding issue without my permission

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Vodafone

Through this complain, i want to highlight my problem regarding unknown number that is [protected] forwarded on my father mobile number [protected]. I tried 2 times to customer care but they are saying it can be resolved from your phone, but i tried through code##21# and call forwarding settings but it is always showing error i.e. "Your carrier doesn't support disabling call forwarding on your number"

i am totally frustrated without my permission how it is possible to activate unknown number on my father phone number. This is completely breach of privacy issue. request you to solve it