Seems to me that Lowell are starting to panic and will use everything they can think of to frighten and intimidate you into paying up.
I am sure that Lowell have many other people doing the same as you are doing and Lowell are running scared. Maybe they should get out of the debt collection business if they cannot take the heat now being fired at them. Just keep doing what you are doing. Keep the faith, look at the posts in which Lowell feature and take heart that you are not alone.
Best regards from Dave
I am the wind that rustles the leaves, I am the heat from the Sun, I am the waves that crash to the shore, I'm just me, 'The Guardian'.
As much as I adore Nature, feel part of Nature and at peace with Nature, I still have an intense dislike Bull_Sh*t.