No, they are separate billing systems.
You could however ask for the BB credit to be refunded to your usual method of payment & then use it to pay (part) of your mobile bill.
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To phone EE CS: Dial Freephone +44 800 079 8586 - Option 1 for Home Broadband & Home Phone or Option 2 for Mobile Phone & Mobile Broadband
ISPs: 1999: Freeserve 48K Dial-Up > 2005: Wanadoo 1 Meg BB > 2007: Orange 2 Meg BB > 2008: Orange 8 Meg LLU > 2010: Orange 16 Meg LLU > 2011: Orange 20 Meg WBC > 2014: EE 20 Meg WBC > 2020: EE 40 Meg FTTC > 2022:EE 80 Meg FTTC SoGEA > 2025 EE 150 Meg FTTP
