Air carrier Pilot reported a communications breakdown between flight crew and ground personnel regarding the scheduled Dangerous Goods cargo loaded on aircraft. After a gate return it was verified that the DG cargo was in fact loaded.

Narrative

While boarding; received Dangerous Goods Form message. [Final] Paperwork not received from ramp prior to push. Queried tug driver; he was told no dangerous goods (DG) on board. Notified Dispatch and pushed. Prior to takeoff Dispatch notified crew chief [that they] thought dangerous goods were on board. Returned to gate to verify. Dangerous goods were indeed on board.The Dangerous Goods Form Paperwork identified DG was expected to be on the plane. Therefore I verified that it was not on the plane when I did not get the paperwork.There was obviously a breakdown in communications. I heard the tug driver asking if there was DG on board and he was told no. After speaking with Dispatch and deciding to go back to the gate; I was told by ZZZ Operations that there is no DG on board. I verified this with Dispatch and she said she just talked to the crew chief and he said he thought it was on board. I asked Operations if they talked to the crew chief and they said no. Now where did Operations get the information that it was not on board? There needs to be better procedures in place with reference to verifying dangerous goods on board.