This is why you ALWAYS put a time deadline in your offers. When I was in the business, I NEVER wrote an open-ended offer, which is what it sounds like you have. The seller can drag it out as long as they feel like, hoping to get other offers in the meantime.
I never played that game. If the seller's agent had some reason why I couldn't personally present the offer and get an acceptance, rejection or counter, one of the three, before I walked out of the seller's house, then I would tell the agent, "I have an offer that expires at midnight tonight. Is your seller going to make themselves available? If we can do it tomorrow, then I will get my buyer to extend the offer until midnight tomorrow." This lit a fire under that agent.
In any case, my buyers never gave a seller more than 24 hours to make a decision. If no decision was made by that time, the offer expired and my buyers moved on to something else.
This tells me that the agent you are working with is not that sharp.