It is seriously frustrating when you pull out a big tangled mess of clothes after a wash. It makes the whole process feel pointless because you've spent time cleaning only to have everything twisted together. The biggest culprit I found wasn't the machine itself but usually the load size. People tend to just cram everything in and assume the machine can handle it. If you are putting in too much laundry, the agitation just can't properly separate or spin the items. Try following this simple method instead. Treat each load as a small, manageable batch. Don't fill the tub past the mid-point of its capacity.
Also, if you have a setting that lets you adjust the spin speed, try lowering it just a notch. Sometimes the high spin cycle forces everything into a tight coil. Running a slightly shorter, gentler spin cycle can help keep the items from knotting up into that solid column.