Try using the OTG with some other mobile that supports the service. if that device too fails to detect the Pendrive. The OTG converted might be damaged.
Try switching sims with other phone, and check if the problem still persists. if no issues with new sim, try getting your primary sim replaced by the Provider. Its less of a phone issue and more of Service Provider.
Try getting Hands on Pro mode through some youtube tutorials. Auto modes dont work well in all conditions. A70 has got a good camera, Pro mode will add even more to the photos.
