Your carrier should not be charging you for inbound SMS, changing SMS enablement providers can usually be done in a few minutes.
I would encourage you to look at Teli, Telnyx & Signalwire, iirc they all support blocking texts from a particular number. Avoid Bandwidth.com unless you want to deal with a long sales funnel and chasing them for API keys they never provide.
I would encourage you to look at Teli, Telnyx & Signalwire, iirc they all support blocking texts from a particular number. Avoid Bandwidth.com unless you want to deal with a long sales funnel and chasing them for API keys they never provide.