advice on how to heat my house

i recently purchased my home in july. installed was a brand new ROVSUN mini split system. i was told it was for both heating and cooling. the cooling part works great but unfortunately the heating is struggling. i live in eastern ohio and it’s been very cold recently. the units are struggling to warm my house. it can barely reach 64 when it’s set to 72. we had to install a baseboard heater in the living room so it wasn’t so cold anymore. i’ve had so many problems with this system and i was wondering what my best option would be to replace it. my house is relatively small only 2 bed 1 bath. the living room and kitchen are one big room. there’s a basement that’s one large room with an open ceiling. i’ve been told to put in a furnace but my house has no ductwork and so i’d have to also have that installed. i’ve heard so many different things from people i’m not sure what to do. any advice would be appreciated.